Transportation Secretary Sean P. Duffy will serve as the interim administrator of NASA, President Donald Trump said Wednesday, weeks after he abruptly rescinded the nomination of entrepreneur Jared Isaacman as the agency’s next leader.

“He will be a fantastic leader of the ever more important Space Agency, even if only for a short period of time,” Trump said of Duffy on social media.

Duffy affirmed the decision, saying on social media shortly after Trump’s post that he was “honored to accept this mission.” The former Wisconsin congressman and reality television star was the second Fox News host — after Pete Hegseth — to be selected by Trump for his Cabinet.

Duffy becomes another senior Trump official to wear multiple hats. Secretary of State Marco Rubio is also serving as interim White House national security adviser and the acting head of the U.S. Agency for International Development. During Trump’s first term,

Mick Mulvaney, the director of the Office of Management and Budget, was named the acting White House chief of staff. In late May, Isaacman was preparing for a confirmation vote in the full Senate when he was told that Trump had rescinded his nomination.

At the time, Trump said on social media that the withdrawal was “after a thorough review of prior associations.” It was unclear what he meant by that, though some Republicans had previously criticized Isaacman for donating to Democrats, The Washington Post reported.

On Sunday, Trump said he had withdrawn the nomination because of the entrepreneur’s ties to Elon Musk and after learning that Isaacman was a “blue blooded Democrat who had never contributed to a Republican.” Trump and Musk, former allies, are in an escalating feud.

In a statement Monday, Isaacman said “the President is entitled to assemble the leadership team he believes will best serve his administration,” but rejected Trump’s characterization of him.

“I have been relatively apolitical — a right-leaning moderate — and my political donations across both parties (though 10x more to Republicans) were disclosed in writing, with rationale, before my nomination was ever submitted to the Senate,” Isaacman said in the statement.

On Wednesday, he backed Duffy’s appointment, saying on social media that NASA “needs political leadership from someone the President trusts and has confidence in.”